A prior art combination switch is described in the following with reference to FIG. 14 and FIG. 15. FIG. 14 shows the structure of a conventional automotive combination switch as viewed from the bottom, FIG. 15 is a side view of the automotive combination switch.
Referring to FIG. 14 and FIG. 15, a light control switch unit 1 houses in it a light switch, a dimming/passing switch, a turning switch and various other switches of the category. A wiper control switch unit 2 houses in it various function switches such as a front windshield wiper switch, a rear windshield wiper switch, a front windshield washer switch, and other switches related to the wiper. Electric signals from the respective light control switch unit 1 and the wiper control switch unit 2 are delivered outside through output connectors 3a, 3b attached to the switch units 1, 2, to be supplied severally to a circuit outside the combination switch (a circuit in an automobile). Numeral 5 represents a main body.
Recently, more and more switching functions are being incorporated in an automotive combination switch, and the relevant signals are processed digitally. In line with such trend, various combination switches of a new type have been developed. These switches deliver the electric signals outside after digitally processing them inside the switch; viz. these are the combination switches for multiplex communication use. In such multiplex communication switches, signals from the light control switch unit 1 and the wiper switch unit 2 are processed altogether in a digital circuit (incorporated in either one of the switch units), and then delivered to an automobile side. Therefore, the number of connectors and the pin counts needed may be decreased as compared with those in a system of FIG. 14 and FIG. 15. However, the combination switches for multiplex communication require a new structure for the electrical coupling among the two units. And, because each of the switch units is assembled in an independent block configuration for easy mounting/detaching from the main body, reliable means for interconnection among the switch units is needed, which accomplishes a reliable coupling during mounting operation absorbing dimensional dispersion of constituent parts or that caused by practical handling in the mounting operation.